export default {
  //为当前模块开启命名空间
  namespaced: true,
  
  //模块的state数据
  state: ()=>({
    //购物车的数组用来存储购物车中每个商品的信息对象
    //每个商品的信息对象都包含如下6个属性  
    // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  mutations: {
    addToCart(state,goods){
      const findResult = state.cart.find(x=>x.goods_id===goods.goods_id)
      if(!findResult){
        state.cart.push(goods)
      }else{
        findResult.goods_count++
      }
      this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state){
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    updateGoodsState(state,goods){
      const findRes = state.cart.find(x=>x.goods_id===goods.goods_id)
      if(findRes){
        findRes.goods_state = goods.goods_state
        // uni.setStorageSync('cart',JSON.stringify(state.cart))
        this.commit('m_cart/saveToStorage')
      }
    },
    updateGoodsCount(state,goods){
      const findRes = state.cart.find(x=>x.goods_id===goods.goods_id)
      if(findRes){
        findRes.goods_count=goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
       // console.log(findRes)
    },
    removeGoodsById(state,goods_id){
      state.cart=state.cart.filter(x=>x.goods_id!==goods_id)
      this.commit('m_cart/saveToStorage')
    },
    updateAllGoodsState(state,newState){
      state.cart.forEach(x=>x.goods_state=newState)
      this.commit('m_cart/saveToStorage')
    }
  },
  getters: {
    // 统计购物车中商品的总数量
    total(state){
      // let c = 0
      // // 循环统计商品的数量，累加到变量 c 中
      // state.cart.forEach(goods=>c+=goods.goods_count)
      // return c
      return state.cart.reduce((total,x)=>{return total+=x.goods_count},0)
    },
    //已勾选的商品数量
    checkedCount(state){
      return state.cart.filter(x=>x.goods_state).reduce((total,item) => total+=item.goods_count,0)
    },
    checkedGoodsAmount(state){
      return state.cart.filter(x=>x.goods_state).reduce((total,item)=>{return total+=item.goods_count*item.goods_price},0).toFixed(2)
      // return state.cart.filter(x=>x.goods_state).reduce((total,item) => total+=item.goods_count,0)
    }
  }
}